Cutting devices especially for sugar beet and other tuberous produce



United States Patent [72] Inventor Helmut Hanke Hagen in Westphalia, Germany [21-] Appl. No. 723,848 [22] Filed Apr. 24. I968 [45] Patented Dec. 29, 1970 [73] Assignee H. Putsch & Company,

Hagen in Westphalia, Germany 32] Priority Apr. 27, 1967 3 3 Germany [31 No. P29,248

[54] CUTTING DEVICES ESPECIALLY FOR SUGAR BEET AND OTHER TUBEROUS PRODUCE 1 1 Claims, 4 Drawing Figs.

[52] U.S. Cl. 146/124 [51] Int. Cl 326d 4/28 [50] Field of Search 146/124, 125. 61. 192

[56] References Cited UNITED STATES PATENTS 864,109 8/1907 Schulte 146/124 2,107,208 2/1938 Nankivell 146/124 Primary ExaminerWillie G. Abercrombie Attorney-Waters, Roditi, Schwartz & Nissen ABSTRACT: A cutter device especially for sugar beet and other tuberous produce which includes a rotary cutting disk driven by a means of a direct current motor via a reduction gear. The direct current motor together with the reduction gear is arranged substantially coaxially to the shaft on which the cutting diskis mounted.

PATENTEDUEEZQIE'B 3550.659

SHEET 2 [IF 2 CURRENT LIMITTING CUTTING DEVICES ESPECIALLY FOR SUGAR BEET AND OTHER TUBEROUS PRODUCE The invention relates to a cutter, more especially for sugar beet and other tu'berousproduce, having a rotary cutting disc which can be driven by a direct current motor via a reduction gear. In the case of cutters of this type known hitherto, the driving motor and/or the reduction gear is arranged in such a way that these driving elements lie generally outside the diameter of the cutter or project beyond this diameter. This is, however, to some extent, of really considerable disadvantage with regard to the required floor space, Accessibility and operation of the cutter.

An object of the invention .is therefore, to avoid this disadvantage and thereby provide a cutter which requires as little floor space as possible and which is well accessible and operable all round.

With this object in view, the present invention provides a cutter device especially for sugar beet and other tuberous produce comprising a rotary cutting disc mounted on a cutting disc shaft, a reduction gear connected to said cutting disc shaft and a direct current electric motor arranged with said reduction gear so as to be substantially coaxial to said cutting disc shaft and adapted to drive said cutting disc via said reduction gear.

The result of this coaxial arrangement of the entire driving arrangement above the cutting disc is that no driving or auxiliary driving elements of any sort project beyond the periphery of the cutter. Through the alignment of the cutting disc shaft, the reduction gear and the motor, the arrangement of an electrical drive directly on the cutting disc shaft leads to a greater overall height of the hopper, which feeds material to be cut and thereby to higher charging shafts, through which the material for cutting has to slide. In order to keep the height of the hopper and thereby the height of the charging shafts as small as possible, it is advantageous for the direct current motor with the reduction gear to be mounted directly above the cutting disc and for the hub of the cutting disc to be drawn downwardly potlike, and above the disc an upwardly open space is formed, into which a cover disc of the cutter with the mounting of the cutting disc shaft engages. The cover disc with its central region receiving the bearing of the cutting disc shaft can thereby likewise be drawn downwardly approximately parallel to the cutting disc.

In the cutter of the invention, the direct current motor to be used must have quite special characteristics for the driving task. Thus, it is for example necessary that the motor in the case of the lowest speed develop its highest torque, which is to be at least between two and a half and three times the rated torque, while in the case of a nonnal cutting operation, the torque variation over the speed range must amount to at least twice the rated torque. Furthermore, even in the case of load fluctuations, the speed of the motor is to remain as constant as possible.

' To this end, preferably a compound-wound motor or a shunt-wound motor with divided auxiliary series winding, which has at least one disconnectable winding part, it used as the direct current motor. The possibility is thereby given that the cutter of the invention starts directly without the use of an accessory drive. An adjustable coupling is no longer necessary, since with the aid of the aforementioned direct current drive a range of adjustment of at least 1:10 can readily be achieved with the driving motor.

The direct current motor can be connected with threephase electrical mains via a rectifier and a bridge circuit. The use either of a controlable rectifier (thyristors) or of a rectifier having a regulating transformer connected in series may be used. The controllable rectifier can be designed as a semicontrolled three-phase bridge and can be designed as a semicontrolled three-phase bridge and can be additionally provided with the conventional protective devices for diodes and thyristors (wirings and the like) and motor-controlled adjusting potentiometer for the adjustment of the operating phase angle. Any excessively high current load of the rectifier upon a too sudden speed adjustment or other load shocks can be avoided by an electronic current limiting device.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a vertical section through an embodiment of the cutter of the invention; I

FIG. 2 is a side elevation of the embodiment shown in FIG. 1;

FIG. 3 is an electrical circuit diagram for use with the DC motor of the cutter of the invention including controllable rectifiers; and

FIG. 4 is an electrical circuit diagram similar to FIG. 3 but including a regulating transformer.

The drawings show a cutter constructed according to the invention and comprising a shaft 1 having a cutting disc 2 mounted thereon. Arranged coaxially above the cutting disc is a driving motor 3 with a reduction gear 4, which are connected directly to the shaft 1. A hub 5 of the cutting disc 2 is in a downwardly projecting. recess in such a way that above it a generally conical space is formed, into which the hub 6 of a cover disc 7 and a mounting 8 of the cutting disc shaft 1 engages. Specifically, as shown in FIG. 1, the cutting disc is fixed to shaft 1, and mounting 8 is secured to the outer housing and rotatably supports the shaft in bearings.

The direct current motor 3 comprises a shunt-wound motor with auxiliary series windings disposed on the reduction gear 4 and rigidly coupled to this latter. The reduction gear 4 can be a spur-wheel special gear or a planetary gear. The gear 4 is disposed on the cover disc 7 supporting the lower end of the charging shafts 10 with the pressure ducts 9 and, as mentioned above, connected directly to the cutting disc shaft 1. This coaxial arrangement of driving motor and reduction gear directly above the cutting disc is of particular advantage with regard to the required floor space, better negotiability and better operation of the machine.

Through the construction of the cutting disc and cover disc in such a way that in the region of their hub they are recessed downwardly in a generally conical manner, a comparatively low arrangement of reduction gear 4 and motor 3 becomes possible. The height of the charging shafts 10 of the cutter can thereby be reduced quite considerably.

Advantageously the driving motor 3 is, as in the case of the illustrated embodiment, seated in a dome ll inside the hopper 10', which on account of the pressure ducts 9 and a necessary insertion aperture in the cover disc for the knife boxes, has at least one, but advantageously two diametrically opposite window-shaped perforations 12, which at the same time serve to enable the removal of the motor 3 and the reduction gear 4 from the dome 11. In order to facilitate the insertion and removal of the motor and of the drive into and from the dome, rails 13 are provided, which are releasably mounted on bracketlike support devices 14, which are fastened to the dome or hopper.

Travelling trolleylike lifting devices 15, with which the motor 3 and reduction gear 4 can, after hooking on these devices, easily be raised and be drawn out of the hopper, without having to detach the hopper itself, are mounted for movement on these rails 13.

FIG. 3 shows a compound motor 20 used as a direct current An electronic current-limiting device is connected to the control device 27 to avoid excessive current in the rectifier upon too sudden a speed adjustment or the like.

FIG. 4 is similar to FIG. 3 except herein instead oftlie 60H trol device 27 and the controlled rectifier in the bridge, a re gulating transformer 23 is connect in series with the rectifiers in bridge 22.

We claim:

1. A cutter device especially for sugar beet and other tuberous produce comprising a hollow charging hopper having an upper inlet and lower outlet, a rotary cutting disc mounted beneath said hopper at the outlet thereof, a cutting disc shaft connected to said disc for driving the same, a reduction gear connected to said cutting disc shaft, and a direct current electric motor assembled with said reduction gear in substantially coaxial relation with said cutting disc shaft and disposed within said hopper to drive said cutting disc via said reduction ear.

8 2. A device according to claim 1, wherein said cutting disc is rotatable about a substantially vertical axis, and said direct current motor with said reduction gear is disposed directly above'the cutting disc, said cutting disc including a depressed central region with a lowered hub and a conical space thereabove, a cover disc fixed to said hopper and including at least a portion engaged in said recess and mounting means secured to said portion of the cover disc and rotatably supporting the cutting disc shaft.

3. A device according to claim 2, wherein said cover disc includes a depressed central region nesting within the central region of said cutting disc.

4. A device according to claim 2, wherein said hopper contains a dome region above said cover disc and said hopper has at least one lateral aperture which extends through said hopper and is adaptable for removing said motor and said reduction gear from the hopper. 'J

5. A device according to claim 4, comprising rails extending through said aperture into said dome region and means forlifting and removing said motor andv reduction gear slidably mounted on said rails. t ,1 Y

6. A device according towclaim 5,: comprising means releasably fastening said railstosaid hopper.

7. A device according to claim-1, wherein said direct current motor is a compound-wound motor.

8. A according to claim 1, wherein said direct current motor is a shunt-wound motor with auxiliary series winding, which has at least one disconnectable winding part.

9. A device according to claim 1, further including rectifier means for connecting said direct current motor to a threephase supply, and control means for said rectifier.

10. A device according to claim 9, wherein said control means comprises a regulating transformer connected in series with said rectifier. t 1

11. A device according to claim 9, wherein said rectifier includes thyristors controlled directly by said control means.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3 SS0 ,659 December 29 1970 Patent No. Dated Inventor(s) Helmut nke It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover sheet [32] "Priority Apr. 27, 1967" should read Priority Apr. 28, 1967 Signed and sealed this 13th day of July 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, J Attesting Officer Commissioner of Patent 

